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.326
METALLURGY OP'IEOK AND STEEL.
Pottstown Iron Company, being^bej'ond the capacity of the-machine at Steel ton, and the determinations of elastic limit are, thereof ore,'not comparable. :
•-•'•                                    TABLE XVI-M,
Influence upon'the Elongation of Changes in Width (Barba).
Number of sample.	Dimensions in inches.			Ratio of -width to thickness.	Elongation; per cent.
	Length.	Width.	Thickness.		
1 2. 3 .4: 5 6 7 8	3.94 8.94 8.94 8.94    , 8.94 8.94 3.94 8.94	0.894 0.787 1.181 1.575 1.964 2.852 2.756 8.150	0.394 0.894 , 0.394 0.894 0.394 0.394 0.394 0.394	1 . 2 3 4 5 6-7 8	81.0 34.0 35.0 87.2 89.0 40,8 38.5 84.5
(3) The elongation increases regularly as the width increases. ... (4) The reduction of .area decreases as the width increases.
The same subject was investigated by.Barba,* his results being ''given in Table XVI-M.   The figures show a continual increase in " elongation until the width is six times the thickness, after which ' the stretch grows less.   The latter point is not important in practice, since there is no occasion to use such a wide section, and in 'plates of ordinary thickness the strength of such pieces is beyond '•the capacity of most machines.
'•'•'      •   •••         ':-         "•••• TABLE XVI-K         •  -:•      •   ' .
Effect of an Increase of Width upon the Elongation.t
Thickness in in.		"Width of piece in inches.				
		1	1H	l*A	»4	3
'H	Number of 'pieces .*...' ....... •	180 57950 26.27	120 57878 26.98	80 68102 28.01	80 67800 29.49	18 67676 80.82
	Average ultimate strength; Ibs.per sq. inch . . Elongation in 8 inches ; per cent .........					
						
%	Number of pieces ....... .  ; ........	20 56680 26.92	',25 57001 26.96	20 66720 27.91	20 . 66860 80.17	20 65870 81.02
	Average ultimate strength; Its. per sq. inch . . •JClongationin 8 inches ; per cent ..... ......					
The increase in elongation in greater widths has been shown by E. A. Custer, of the Baldwin Locomotive Works, Philadelphia, Pa.,
:' * Resistance des Materiaua:-; Metnoires de la Societe des Ingenieurs Civils, Vol. 1^18^
Pr682.................._................        ......,....'„.    ,'.......
t E. A. Ouster, private •communication.        :              " '